JP2008310119A - Antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film with: high manufacturing efficiency; high uniformity; excellent adhesion; and extremely low reflection, wherein the antireflection film is constituted of three-layer thin film and a high refractive index layer and a middle refractive index layer can be formed by one application process. <P>SOLUTION: The middle refractive index layer, the high refractive index layer and a low refractive index layer, each of which has film thickness of ≤150 nm, are laminated in this order on a film base material or on the film base material having a hard coat layer to form the antireflection film. The high refractive index layer contains first metal oxide particulates having surface ornamentation by a specific polymer and mean grain size of ≤50 nm. The middle refractive index layer contains second metal oxide particulates which are different from the first metal oxide particulates and have mean grain size of ≤50 nm. Further, the middle refractive index layer and the high refractive index layer are two layers separated from one application film or the middle refractive index layer and the high refractive index layer are two layers obtained by simultaneous multilayer application. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antireflection film. In particular, the high refractive index layer and the medium refractive index layer can be formed by a single coating process, and the production efficiency is high. Related to film.

Anti-reflective films are placed on the display surface in various image display devices such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescence display (ELD), cathode ray tube display (CRT), etc. In addition to preventing a decrease in contrast due to reflection of external light and reflection of an image, high physical strength (such as scratch resistance) and transparency are required.
An antireflection film having an extremely low reflectance with an average reflectance of 1% or less has different refractive indexes of a medium refractive index layer, a high refractive index layer, and a low refractive index layer on a substrate or a hard-coated substrate. It is known to be obtained by laminating a certain three layers of thin films (see, for example, Patent Documents 1 and 2).

These antireflection films are usually produced by a coating method, but laminating three layers of thin films having different refractive indexes requires at least three coating steps, resulting in high production costs. Had the problem.
Regarding this problem, a technique capable of forming two or more layers from one coating film has been disclosed (see, for example, Patent Documents 3 and 4). However, this technique is excellent in that an antireflection film that requires three layers can be produced with a small number of coating processes, but there is no freedom in choice of coating solvent, and it is difficult to control the drying process after coating. It was difficult to obtain a uniform antireflection film due to variation in conditions and non-uniformity of drying.
JP 2003-121606 A JP 2003-262702 A JP 2006-206932 A JP 2007-038199 A

  In the antireflection film having a three-layer thin film structure, the present invention can form a high refractive index layer and a medium refractive index layer in a single coating step, has a high production efficiency, and a highly uniform and extremely low reflectance. An object is to provide an antireflection film.

The present invention is a technique for forming a high-refractive index layer and a medium-refractive index layer in a single coating process in an antireflection film having a three-layer thin film structure. In this technique, the fine particles are surface-modified with a specific compound that reduces the surface energy so that they are spontaneously distributed on the surface in the coating liquid film.
Since the antireflective film having a three-layer thin film structure is designed so that both the high refractive index layer and the medium refractive index layer have a film thickness of 150 nm or less, the above-described high refractive index metal oxide fine particles having a reduced surface energy are In addition, the metal oxide fine particles for the middle refractive index layer can occupy the lower layer, and as a result, the high refractive index layer and the middle refractive index layer can be separated. Can do. Such a phenomenon can be manifested when the average particle diameter of the metal oxide fine particles of the high refractive index layer and the metal oxide fine particles of the medium refractive index layer is 50 nm or less and ultrafine particles.
In the present invention, the specific compound for reducing the surface energy for modifying the surface of the metal oxide fine particles includes a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particles. The second is a polymer having a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particles.
The object of the present invention is achieved by an antireflection film having the following constitution.

(1) An antireflection film in which a medium refractive index layer, a high refractive index layer, and a low refractive index layer, each having a film thickness of 150 nm or less, are laminated in this order on a film substrate or a film substrate having a hard coat layer. Because
The high refractive index layer contains first metal oxide fine particles having an average particle diameter of 50 nm or less, and the polymer has a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particles. The first metal oxide fine particles are surface-modified,
The middle refractive index layer contains second metal oxide fine particles having an average particle size different from the first metal oxide fine particles of 50 nm or less,
Further, the medium refractive index layer and the high refractive index layer are two layers separated from one coating film, or the middle refractive index layer and the high refractive index layer are two layers coated simultaneously by multilayer coating. the film.

(2) An antireflection film in which a medium refractive index layer, a high refractive index layer, and a low refractive index layer, each having a thickness of 150 nm or less, are laminated in this order on a film substrate or a film substrate having a hard coat layer. Because
The high refractive index layer contains first metal oxide fine particles having an average particle diameter of 50 nm or less, and the polymer has a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particles. The first metal oxide fine particles are surface-modified,
The middle refractive index layer contains second metal oxide fine particles having an average particle size different from the first metal oxide fine particles of 50 nm or less,
Further, the medium refractive index layer and the high refractive index layer are two layers separated from one coating film, or the middle refractive index layer and the high refractive index layer are two layers coated simultaneously by multilayer coating. the film.

(3) The reflection according to (1) above, wherein the polymer having a unit having the fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particle has a structure represented by the following general formula [I] Prevention film.

(In the formula, R 1 and R 2 represent a hydrogen atom or an alkyl group. L 1 represents a divalent linking group having 10 or less carbon atoms, n 1 represents 0 or 1, and R f represents —CF ₃ or —CF ₂ H. P represents an integer of 1 to 10, L represents a divalent linking group having 10 or less carbon atoms, m represents 0 or 1, A represents a hydroxyl group or a hydrolyzable group, x represents a mole %.)

(4) The reflection according to (2) above, wherein the polymer having a unit having the polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particle has a structure represented by the following general formula [II]: Prevention film.

(In the formula, R 1 and R 2 represent a hydrogen atom or an alkyl group. L 2 represents a divalent linking group having 10 or less carbon atoms, n 2 represents 0 or 1, and R 11 to R 15 are the same or different. Each represents a hydrogen atom or an alkyl or aryl group having 1 to 5 carbon atoms, q is an integer of 10 to 500, L represents a divalent linking group having 10 or less carbon atoms, and m is 0 or 1 represents A, a hydroxyl group or a hydrolyzable group, and y represents mol%.)

(5) The antireflection film according to any one of (1) to (4), wherein the first metal oxide fine particles are fine particles of titanium oxide or zirconium oxide.

(6) The antireflection film according to any one of (1) to (5), wherein the second metal oxide fine particles are conductive zinc oxide-based fine particles.

  The high refractive index layer and the medium refractive index layer can be formed by a single coating step, and an antireflection film having a very low reflectance with high uniformity and good adhesion can be obtained.

Hereinafter, the antireflection film of the present invention will be described.
[Layer structure of optical film]
The antireflection film of the present invention has a medium refractive index layer, a high refractive index layer, and a low refractive index layer in this order on a transparent substrate (also referred to as a support) in which the thickness of each layer is 150 nm or less, Depending on the purpose, other functional layers can be provided alone or in multiple layers.
As a preferred embodiment, there can be mentioned an antireflection film laminated on the substrate in consideration of the refractive index, the film thickness, the number of layers, the layer order, etc. so that the reflectance is reduced by optical interference. The antireflection film is formed by combining a high refractive index layer having a higher refractive index than the base material and a low refractive index layer having a lower refractive index than the base material. As a configuration example, three layers having different refractive indexes from the base material side, a medium refractive index layer (a layer having a higher refractive index than the base material or the hard coat layer and a lower refractive index than the high refractive index layer) / high Some of them are laminated in the order of refractive index layer / low refractive index layer, and others in which more antireflection layers are laminated have also been proposed. Among them, in view of durability, optical characteristics, cost, productivity, etc., it is preferable to apply a medium refractive index layer / high refractive index layer / low refractive index layer in this order on a substrate having a hard coat layer. Examples include the configurations described in Kaihei 8-122504, 8-110401, 10-300902, JP-A 2002-243906, JP-A 2000-111706, and the like.
Other functions may be imparted to each layer, for example, an antifouling low refractive index layer or an antistatic high refractive index layer (eg, JP-A-10-206603, JP-A-2002). -243906 publication etc.) etc. are mentioned.

The example of the preferable layer structure of the film of the said aspect is shown below. In the following configuration, the film substrate refers to a support composed of a film.
Film base / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer / film base / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer / moisture proof layer / Film substrate / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer / moisture-proof layer / film substrate / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer / film Substrate / hard coat layer / conductive layer / medium refractive index layer / high refractive index layer / low refractive index layer / film substrate / hard coat layer / conductive medium refractive index layer / high refractive index layer / low refractive index layer Moisture proof layer / film substrate / hard coat layer / conductive medium refractive index layer / high refractive index layer / low refractive index layer Each component layer will be described below.

(Low refractive index layer)
In the present invention, the low refractive index layer is located on the outermost surface side of the antireflection film and is the layer having the lowest refractive index among the layers of the antireflection film.
The refractive index of the low refractive index layer is preferably 1.50 or less, more preferably 1.40 or less, and most preferably 1.20 to 1.40.

  The thickness of the low refractive index layer is essential to be 150 nm or less, more preferably 20 nm to 150 nm, and most preferably 40 nm to 130 nm.

The low refractive index layer preferably contains a fluorine-containing compound having an ethylenically unsaturated group that can be cured by ultraviolet irradiation as a low refractive index material.
Specifically, the ethylenically unsaturated group means that the terminal is a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, or an isopropenyl group, and an acryloyl group or a methacryloyl group is particularly preferable.
Although one ethylenically unsaturated group may be present in one molecule, it is more preferable that the fluorine-containing compound having an ethylenically unsaturated group has two or more ethylenically unsaturated groups in one molecule.

  As a specific example of the fluorine-containing compound having two or more ethylenically unsaturated groups, a known technique can be used, for example, fluorine-containing polyfunctional (meth) acrylic acid described in JP-A-9-301925. Esters, fluorine-containing polyfunctional (meth) acrylic acid esters described in JP-A-10-182745, fluorine-containing polyfunctional (meth) acrylic acid esters described in JP-A-10-182746, JP-A-2001-72646 Mention may be made of the fluorine-containing polyfunctional (meth) acrylic acid esters described in the publication.

  Further, the fluorine-containing compound having an ethylenically unsaturated group is preferably a polymer, and the number average molecular weight in terms of polystyrene measured by tetrahydrofuran (hereinafter also referred to as THF) as a solvent by gel permeation chromatography (hereinafter also referred to as GPC). Is preferably 1000 to 500,000. When the number average molecular weight is 500,000 or less, the viscosity of the composition is suppressed and thinning becomes easy.

For the fluorine-containing polymer having an ethylenically unsaturated group, which is preferable in the present invention, specifically, a known technique can be used. For example, JP 2005-89536 A, JP 2005-290133 A, JP The ethylenically unsaturated group containing fluoropolymer described in 2006-36835 can be mentioned.

  The addition amount of the fluorine-containing compound having an ethylenically unsaturated group is preferably 10 to 100% by mass, more preferably 20 to 90% by mass, and more preferably 30 to 90% by mass with respect to 100% by mass of the solid content of the low refractive index layer. % Is most preferred.

In the present invention, the low refractive index layer preferably contains silica fine particles having an average particle diameter of 1 nm to 100 nm. The silica fine particles may be solid particles, but it is preferable to use hollow silica fine particles in order to lower the refractive index.
The hollow silica fine particles have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1.35, and still more preferably 1.17 to 1.30. The refractive index here represents the refractive index of the whole particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica fine particles. At this time, when the radius of the cavity in the particle is a and the radius of the particle outer shell is b, the porosity x is calculated by the following formula (VIII).
(Formula ^{VIII) x = (4πa 3/} 3) / (4πb 3/3) × 100
The porosity x is preferably 10 to 60%, more preferably 20 to 60%, and most preferably 30 to 60%. If the hollow silica fine particles are made to have a lower refractive index and a higher porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. Therefore, the low refractive index is less than 1.17 from the viewpoint of scratch resistance. Rate particles do not hold.
The refractive index of these hollow silica fine particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

  The addition amount of these silica fine particles or hollow silica fine particles is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and most preferably 30 to 60% by mass with respect to 100% by mass of the solid content of the low refractive index layer. preferable.

(High refractive index layer)
In the present invention, the high refractive index layer is an adjacent layer immediately below the low refractive index layer from the surface side of the antireflection film, and is a layer having a higher refractive index than the low refractive index layer.

  The refractive index of the high refractive index layer is preferably 1.60 to 2.00, more preferably 1.65 to 1.90, and most preferably 1.70 to 1.85. .

  In the present invention, the film thickness of the high refractive index layer must be within a range in which the metal oxide fine particles in the high refractive index layer can be uniformly contained, and it is essential that the film thickness be 150 nm or less. It is preferably ˜150 nm, more preferably 30 to 130 nm.

In the high refractive index layer, a known metal oxide type can be selected as the first metal oxide fine particles according to the necessity of adjusting the refractive index, but it is particularly preferable to use titanium oxide fine particles or zirconium oxide fine particles. .
Further, the average particle diameter of the first metal oxide fine particles has an appropriate range in which the metal oxide fine particles in the high refractive index layer can be uniformly contained, and is essential to be 50 nm or less, particularly 5 to 5 nm. It is preferable that it is 40 nm. The average particle diameter of the metal oxide fine particles can be measured by an electron micrograph or the like.

The first metal oxide fine particles of the high refractive index layer are contained in an amount of 50 to 95% by mass with respect to the total solid content of the high refractive index layer from the viewpoint of uniformly containing the metal oxide fine particles in the high refractive index layer. It is preferable to contain 60 to 90% by mass.

  Below, a polymer having a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particle, and a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particle A polymer having

A polymer having a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particle In one of the present invention, the first metal oxide fine particle has a unit having a fluorine-containing alkyl group and a metal oxide. It is surface-modified by a polymer having a unit having a reactive group that modifies the surface of physical particles.

In the present invention, the mass average molecular weight of the polymer having a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particles is 5000 to 100,000 when a component having a molecular weight of less than 300 is excluded. Preferably, 10,000 to 80,000 is more preferable, and 10,000 to 50,000 is most preferable.
Here, the mass average molecular weight and the molecular weight are converted to polystyrene by GTH analyzer using a column of TSKgel GMHxL, TSKgel G4000HxL, TSKgel G2000HxL (all trade names manufactured by Tosoh Corporation), and solvent THF and differential refractometer detection. The content is the area% of the peak in the molecular weight range when the peak area of the component having a molecular weight of 300 or more is defined as 100%.

  In particular, the polymer having a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particles preferably has a structure represented by the following general formula [I].

In the formula, R1 and R2 represent a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.
L1 represents a divalent linking group having 10 or less carbon atoms, preferably a linking group represented by -COO-L'- or -OL- (L 'is an alkylene group), and n1 is 0 or 1 is represented, preferably 1.
Rf represents —CF ₃ or —CF ₂ H, preferably —CF ₃ , and p is an integer of 1 to 10, preferably 3 to 6.
L represents a divalent linking group having 10 or less carbon atoms, and is preferably a linking group represented by —COO-L′— or —O—L′— (L ′ is an alkylene group), and m is 0 or 1 is represented.
A represents a hydroxyl group or a hydrolyzable group, preferably a methoxy group or an ethoxy group.
x represents mol%, preferably 60 to 99.9, and particularly preferably 70 to 95.

  Specific examples of the polymer having a unit having a fluorine-containing alkyl group having a structure represented by the general formula [I] and a unit having a reactive group for modifying the surface of the metal oxide fine particles are shown in Table 1 below. Is not to be done.

  For example, in Example I-1, the monomer “F-5” obtained using the telomer method described in JP-A No. 2004-163610 and 3- (trimethoxysilyl) propyl acrylate have a desired molar ratio. It can synthesize | combine by mixing in an organic solvent, adding a general purpose radical polymerization initiator, and making it polymerize.

  The polymer having a unit having a fluorine-containing alkyl group having the structure represented by the general formula [I] and a unit having a reactive group for modifying the surface of the metal oxide fine particles is 1% by mass to the inorganic oxide fine particles. It is preferable to use 100 mass%, More preferably, it is 5 mass%-80 mass%, More preferably, it is 10 mass%-50 mass%.

A polymer having a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particle In one of the present invention, the first metal oxide fine particle is a unit having a polydialkylsiloxane group and a metal oxide. It is surface-modified by a polymer having a unit having a reactive group that modifies the surface of physical particles.

In the present invention, the mass average molecular weight of the polymer having a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particles is 10000 to 200000 when a component having a molecular weight of less than 300 is excluded. Preferably, 20000 to 150,000 are more preferable, and 30000 to 100,000 are most preferable.
Here, the mass average molecular weight and the molecular weight are converted to polystyrene by GTH analyzer using a column of TSKgel GMHxL, TSKgel G4000HxL, TSKgel G2000HxL (all trade names manufactured by Tosoh Corporation), and solvent THF and differential refractometer detection. The content is the area% of the peak in the molecular weight range when the peak area of the component having a molecular weight of 300 or more is defined as 100%.

  In particular, the polymer having a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particles preferably has a structure represented by the following general formula [II].

In the formula, R1 and R2 represent a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.
L2 represents a divalent linking group having 10 or less carbon atoms, preferably a linking group represented by -COO-L'- or -OL- (wherein L 'is an alkylene group), and n2 is 0 or 1 is represented, preferably 1.
R11 to R15 may be the same or different and each represents a hydrogen atom or an alkyl or aryl group having 1 to 5 carbon atoms, preferably all are methyl groups, and q is an integer of 10 to 500. , Preferably 10 to 200.
L represents a divalent linking group having 10 or less carbon atoms, and is preferably a linking group represented by —COO-L′— or —O—L′— (L ′ is an alkylene group), and m is 0 or 1 is represented.
A represents a hydroxyl group or a hydrolyzable group, preferably a methoxy group or an ethoxy group.
y represents mol%, preferably 10 to 90, and particularly preferably 30 to 90.

  Specific examples of the polymer having a unit having a polydialkylsiloxane group having a structure represented by the general formula [II] and a unit having a reactive group for modifying the surface of the metal oxide fine particles are shown in Table 2 below, but are limited thereto. Is not to be done.

  For example, in Example II-1, one-end silaplane “FM-0711” manufactured by Chisso Corporation and 3- (trimethoxysilyl) propyl acrylate are mixed in an organic solvent so as to have a desired molar ratio. It can synthesize | combine by adding the radical polymerization initiator of and polymerizing.

  The polymer having a unit having a polydialkylsiloxane group represented by the general formula [II] and a unit having a reactive group for modifying the surface of the metal oxide fine particles is 1% by mass to 100% by mass with respect to the inorganic oxide fine particles. It is preferable to use, More preferably, it is 5 mass%-80 mass%, More preferably, it is 10 mass%-50 mass%.

Further, the high refractive index layer preferably contains a polyfunctional monomer having two or more (meth) acryloyl groups in one molecule.
As polyfunctional monomers, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol Di (meth) acrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, diethylene glycol bis β- (meth) acryloyloxypropionate, trimethylolethane Tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (2-H Roxyethyl) isocyanate di (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,3-bis (meth) acryloyloxyethyloxymethyl [2.2.1] heptane, poly 1,2-butadiene di (meth) acrylate 1,2-bis (meth) acryloyloxymethylhexane, nonaethylene glycol di (meth) acrylate, tetradecanethylene glycol di (meth) acrylate, 10-decanediol (meth) acrylate, 3,8-bis (meth) acryloyl Oxymethyltricyclo [5.2.10] decane, hydrogenated bisphenol A di (meth) acrylate, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 1,4-bis ((meta ) Acryloyloxymethyl Examples thereof include cyclohexane, hydroxypivalin sun ester neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and epoxy-modified bisphenol A di (meth) acrylate. Only one type of polyfunctional monomer may be used, or two or more types may be used in combination.

  In the present invention, the addition amount of these polyfunctional monomers is preferably 1 to 50% by mass, more preferably 1 to 40% by mass, and 3 to 30% by mass with respect to 100% by mass of the solid content of the high refractive index layer. Most preferred.

(Medium refractive index layer)
In the present invention, an intermediate refractive index layer is provided between a transparent support provided with a hard coat layer or an antiglare layer and a high refractive index layer.
The refractive index of the medium refractive index layer is adjusted to be an intermediate value between the refractive index of the hard coat layer or the antiglare layer and the high refractive index layer, and the value is 1.55 to 1.80. preferable.

  In the present invention, the film thickness of the medium refractive index layer must be within a range in which the metal oxide fine particles in the medium refractive index layer can be uniformly contained, and it is essential that the film thickness be 150 nm or less. It is preferably ˜150 nm, more preferably 30 to 130 nm.

  The average particle diameter of the second metal oxide fine particles has an appropriate range in which the metal oxide fine particles in the medium refractive index layer can be uniformly contained, and is essential to be 50 nm or less, particularly 5 to 5 nm. It is preferable that it is 40 nm.

  The second metal oxide fine particles in the medium refractive index layer are preferably contained in an amount of 50 to 95% by mass, more preferably 60 to 90% by mass, based on the total solid content of the medium refractive index layer.

In the present invention, it is preferable that the second metal oxide fine particles contained in the medium refractive index layer are not surface-modified with the polymer, and a metal capable of adjusting the refractive index of the medium refractive index layer, such as titanium oxide and zirconium oxide. Oxide fine particles may be used, but conductive zinc oxide fine particles are particularly suitable in that the refractive index is in an appropriate range of 1.9 to 2.0 and that antistatic properties can be imparted. It can be preferably used from both viewpoints.
The conductive zinc oxide-based fine particles are preferably doped with a trivalent metal element in order to develop conductivity, and are particularly preferably aluminum-containing zinc oxide fine particles doped with aluminum.

-Aluminum-containing zinc oxide particles The primary particle diameter of aluminum-containing zinc oxide particles can usually be 5 nm to 100 nm. The crystal structure is not particularly limited, but a monoclinic system or the like can be used. The primary particle diameter of the aluminum-containing zinc oxide particles can be measured, for example, as the number average particle diameter by observation with a transmission electron microscope. When the particles are not spherical, the average of the major axis and the minor axis is the particle diameter, and when the ratio of the major axis / minor axis is 2 or more, the minor axis is the particle diameter.

The aluminum-containing zinc oxide particles have a spherical shape, a hollow shape, a porous shape, a rod shape, a plate shape, a fiber shape, or an indefinite shape, and preferably a spherical shape.
Examples of such commercially available aluminum-containing zinc oxide particles include Hakusui Tech Co., Ltd. trade names: Passet AB, Passet AK, Passet CK, Sakai Chemical Industry Co., Ltd. trade name: SC-18.

Further, the medium refractive index layer preferably contains a polyfunctional monomer having two or more (meth) acryloyl groups in one molecule.
The polyfunctional monomer is the same as described for the high refractive index layer.
The addition amount of these polyfunctional monomers is preferably 1 to 50% by mass, more preferably 1 to 40% by mass, and most preferably 3 to 30% by mass with respect to 100% by mass of the solid content of the medium refractive index layer.

(Film substrate)
The film substrate is not particularly limited as long as it has an excellent visible light transmittance (preferably a light transmittance of 90% or more) and excellent transparency (preferably a haze value of 1% or less). Specifically, for example, a film made of a transparent polymer such as a polyester polymer such as polyethylene terephthalate and polyethylene naphthalate, a cellulose polymer such as diacetyl cellulose and triacetyl cellulose, a polycarbonate polymer, and an acrylic polymer such as polymethyl methacrylate. Is mentioned. In addition, styrene polymers such as polystyrene and acrylonitrile / styrene copolymer, polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, olefin polymers such as ethylene / propylene copolymer, vinyl chloride polymers, nylon and aromatic polyamides. Examples thereof include a film made of a transparent polymer such as an amide polymer. Furthermore, imide polymers, sulfone polymers, polyether sulfone polymers, polyether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers Examples thereof include a film made of a transparent polymer such as a polymer, an epoxy-based polymer, and a blend of the aforementioned polymers. In particular, those having a small optical birefringence are preferably used.

  When the antireflection film according to the present embodiment is used as a protective film for a polarizing plate, the film base material is preferably triacetyl cellulose, polycarbonate, acrylic polymer, polyolefin having a cyclic or norbornene structure, or the like. . The film base material may be a polarizer itself described later. With such a configuration, a protective layer made of TAC or the like is not required and the structure of the polarizing plate can be simplified, so that the number of manufacturing steps can be reduced and the production efficiency can be improved. Further, the polarizing plate can be further thinned. Further, the antiglare hard coat film also serves as a cover plate attached to the surface of the liquid crystal cell.

  The thickness of the film substrate can be appropriately determined, but is generally about 10 to 500 μm in consideration of workability such as strength and handleability and thin layer properties. 20-300 micrometers is especially preferable, and 30-200 micrometers is more preferable. Furthermore, it does not restrict | limit especially as a refractive index of a film base material, It is usually about 1.30-1.80, It is especially preferable that it is 1.40-1.70.

(Coating solvent)
In the present invention, the coating solvent used for the high refractive index layer and the medium refractive index layer is not particularly limited, and conventionally known solvents can be used. Solvents such as toluene, methyl ethyl ketone, and isobutyl ketone used for general coating can be used.

(Drying process)
In the present invention, there is no particular limitation on the drying step after the coating liquid for the high refractive index layer and the medium refractive index layer is applied on the film substrate or the film substrate having the hard coat layer. Use a method that can be used for normal post-coating drying even when the refractive index layer is two layers separated from the coating film of 1 or when the middle refractive index layer and the high refractive index layer are two layers coated simultaneously. Can do.

(Method for forming each layer)
Each layer of the antireflection film of the present invention can be formed by the following coating method, but is not limited to this method.
Dip coating method, air knife coating method, curtain coating method, roller coating method, wire bar coating method, gravure coating method and extrusion coating method (die coating method) (see US Pat. No. 2,681,294), micro gravure coating method, etc. Known methods are used, and among them, the micro gravure coating method and the die coating method are preferable.

  Here, the micro gravure coating method refers to a gravure roll having a diameter of about 10 to 100 mm, preferably about 20 to 50 mm and having a gravure pattern engraved on the entire circumference, below the support and in the transport direction of the support. While rotating the gravure roll in a reverse direction, the surplus coating liquid is scraped off from the surface of the gravure roll by a doctor blade, and a predetermined amount of coating liquid is applied to the lower surface of the support at a position where the upper surface of the support is in a free state. The coating method is characterized in that the coating is performed by transferring the liquid. A roll-shaped transparent support can be continuously unwound, and at least one layer can be coated on one side of the unwound support by a microgravure coating method.

  As coating conditions by the micro gravure coating method, the number of gravure patterns imprinted on the gravure roll is preferably 50 to 800 lines / inch, more preferably 100 to 300 lines / inch, and the depth of the gravure pattern is 1 to 600 μm. Is preferable, 5 to 200 μm is more preferable, the rotation speed of the gravure roll is preferably 3 to 800 rpm, more preferably 5 to 200 rpm, and the conveyance speed of the support is 0.5 to 100 m / min. It is preferably 1 to 50 m / min.

In the present invention, the two layers in which the medium refractive index layer and the high refractive index layer are simultaneously coated are that the high refractive index layer is laminated on the medium refractive index layer without wet process. In order to do this, the layers may be sequentially stacked without being dried by an extrusion coater, or may be simultaneously stacked using a slot die having a plurality of slits.
In the present invention, simultaneous multi-layering by a slot die having a plurality of slits is preferable.

(Curing method)
In the present invention, the coated and dried antireflection film can be cured by heat and / or ultraviolet irradiation. Here, curing by ultraviolet irradiation means low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, etc., ArF excimer laser, KrF excimer laser, excimer lamp or synchrotron radiation. This refers to curing the film by irradiating the dried film with ultraviolet light using a light source such as light.
The irradiation conditions vary depending on individual lamps, but the amount of light irradiated is preferably 20~10000mJ / cm ^2, more preferably from 100 to 2000 mJ / cm ^2, particularly preferably 400~2000mJ / cm ^2.
In the case of curing with ultraviolet rays, each layer may be irradiated one by one or after lamination.

(Image display device)
The antireflection film of the present invention is preferably used as a surface film of a liquid crystal panel screen.
The liquid crystal panel used includes a VA mode in which rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied, and is horizontally aligned when a voltage is applied, and an MVA mode in which the multi-domain is formed, and a nematic The IPS mode in which switching is performed by applying a lateral electric field to the liquid crystal, and the OCB mode in which rod-like liquid crystalline molecules are aligned substantially symmetrically at the upper and lower portions of the liquid crystal cell are modes having a wide viewing angle. The antireflection film can be preferably used.
Furthermore, the higher the resolution of the liquid crystal panel, the more preferably the antireflection film of the present invention can be used. In particular, the liquid crystal panel is preferably used for a high-resolution liquid crystal panel called full-spec high-definition having 1920 × 1080 or 1440 × 1080. Can be used.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

[Comparative Example 1: Antireflection film 101]
(Preparation of coating liquid A for hard coat layer)
The following composition was put into a mixing tank and stirred to obtain a hard coat layer coating solution.
750.0 parts by mass of trimethylolpropane triacrylate (Biscoat # 295 (manufactured by Osaka Organic Chemical Co., Ltd.)), 270.0 parts by mass of poly (glycidyl methacrylate) having a mass average molecular weight of 15000, 730.0 parts by mass of methyl ethyl ketone, 500 cyclohexanone 0.0 parts by mass and 50.0 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) were added and stirred, and filtered through a polypropylene filter having a pore size of 0.4 μm to form a hard coat layer. Coating solution A was prepared.

(Preparation of coating liquid A for medium refractive index layer)
Preparation of Aluminum-Containing Zinc Oxide Fine Particle Dispersion (A-1) Aluminum-Containing Zinc Oxide Fine Particles (manufactured by Hakusui Tech Co., Ltd., Passetto CK (trade name), primary particle size 30 nm), dispersant (manufactured by Enomoto Kasei Co., Ltd., PLAAD) ED211 (product name)
: High molecular polycarboxylic acid amidoamine salt having a number average molecular weight of 40,000, solid content 50%) and methyl ethyl ketone were mixed in a blending amount of 30/3/67 (mass ratio). 2 g of this dispersion was weighed on an aluminum dish, dried on a hot plate at 175 ° C. for 1 hour, and weighed to determine the solid content, which was 33%. Also, 2 g of this dispersion was weighed into a magnetic crucible, pre-dried on a hot plate at 80 ° C. for 30 minutes, and baked in a muffle furnace at 750 ° C. for 1 hour. When calculated, it was 30%.
In a 50 ml plastic bottle of a paint shaker, 40 g of glass beads (manufactured by TOSHINRIKO, BZ-01, bead diameter 0.1 mm, volume of about 16 ml) and the above mixed solution (30 g) are dispersed for 8 hours, and aluminum-containing zinc oxide fine particles are dispersed A liquid (A-1) was obtained.

  21.0 parts by mass of the aluminum-containing zinc oxide fine particle dispersion (A-1), 2.7 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), a photopolymerization initiator (Irgacure 184, Ciba -Specialty Chemicals Co., Ltd.) 0.1 mass part, methyl ethyl ketone 73.7 mass part, and cyclohexanone 2.5 mass part were added and stirred, and the coating liquid A for medium refractive index layers was prepared.

(Preparation of coating liquid A for high refractive index layer)
A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate in 21.0 parts by mass of zirconium oxide fine particle sol (methyl ethyl ketone zirconium sol, average particle diameter 10 nm, zirconium oxide mass concentration 30%, manufactured by Sumitomo Osaka Cement Co., Ltd.) DPHA) 2.7 parts by mass, 0.1 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.), 73.7 parts by mass of methyl ethyl ketone and 2.5 parts by mass of cyclohexanone were added and stirred. Then, a coating solution A for a high refractive index layer was prepared.

(Preparation of coating solution for low refractive index layer)
(Synthesis of perfluoroolefin copolymer P-1)

  In the above structural formula, 50:50 represents a molar ratio.

Into a stainless steel autoclave with a stirrer of 100 ml, 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether and 0.55 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Furthermore, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 0.53 MPa (5.4 kg / cm ² ). The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 0.31 MPa (3.2 kg / cm ² ), the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 g of polymer was obtained. Next, 20 g of the polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of perfluoroolefin copolymer P-1. The resulting polymer had a refractive index of 1.422.

(Preparation of sol solution a)
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), diisopropoxyaluminum ethyl acetoacetate (trade name: Kerope EP) -12, manufactured by Hope Pharmaceutical Co., Ltd.) 3 parts were added and mixed, and then 31 parts of ion exchange water was added and reacted at 61 ° C. for 4 hours, followed by cooling to room temperature to obtain sol solution a. The mass average molecular weight was 1620, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Preparation of hollow silica particle dispersion)
Hollow silica particle fine particle sol (isopropyl alcohol silica sol, CS60-IPA manufactured by Catalytic Chemical Industry Co., Ltd., average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20%, silica particle refractive index 1.31) in 500 parts, acryloyloxy After 30.5 parts of propyltrimethoxysilane and 1.51 parts of diisopropoxyaluminum ethyl acetate were added and mixed, 9 parts of ion-exchanged water was added. After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 parts of acetylacetone was added to obtain a dispersion. Then, while adding cyclohexanone so that the silica content was substantially constant, the solvent was replaced by distillation under reduced pressure at a pressure of 30 Torr. Finally, a dispersion having a solid content concentration of 18.2% was obtained by adjusting the concentration. When the amount of IPA remaining in the obtained dispersion was analyzed by gas chromatography, it was 0.5% or less.

  Using the obtained hollow silica particle dispersion or sol solution, a composition having the following composition is mixed, and the resulting solution is stirred and then filtered through a polypropylene filter having a pore size of 1 μm to obtain a coating solution for a low refractive index layer. A was prepared.

(Composition of coating liquid A for low refractive index layer)
DPHA 1.6g
P-1 6.3g
Hollow silica particle dispersion (18.2%) 60.0 g
RMS-033 0.5g
Irgacure 907 0.3g
Sol liquid a 7.4 g
MEK 263.9g
Cyclohexanone 10.0g

The compounds used are shown below.
P-1: Perfluoroolefin copolymer P-1
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)
Hollow silica particle dispersion: Hollow silica particle sol surface-modified with the acryloyloxypropyltrimethoxysilane, solid content concentration 18.2%.
MEK: methyl ethyl ketone RMS-033: reactive silicone (manufactured by Gelest Co., Ltd.)
・ Irgacure 907: Photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.)

(Preparation of hard coat layer A)
On a triacetyl cellulose film (TD80UF, manufactured by Fuji Film Co., Ltd., refractive index 1.48) as a transparent support having a layer thickness of 80 μm, the hard coat layer coating solution A having the above composition was applied using a gravure coater. . After drying at 100 ° C., an irradiance of 400 mW / cm using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm while purging with nitrogen so that the oxygen concentration becomes 1.0 vol% or less. ^2. Irradiation amount 300mJ
The hardened layer A having a thickness of 8 μm was formed by curing the coating layer by irradiating UV light of / cm ² .

(Preparation of medium refractive index layer, high refractive index layer, low refractive index layer)
On the above hard coat layer A, the medium refractive index layer coating liquid A, the high refractive index layer coating liquid A, and the low refractive index layer coating liquid A were sequentially applied using a gravure coater.
The middle refractive index layer had a refractive index of 1.62 and a film thickness of 60 nm, the high refractive index layer had a refractive index of 1.72 and a film thickness of 110 nm, and the low refractive index layer had a refractive index of 1.36 and a film thickness of 90 nm. . In addition, the measurement of the refractive index of each layer applied the coating liquid of each layer to the glass plate so that it might become a thickness of about 4 micrometers, and measured it with the Abbe refractometer (made by Atago Co., Ltd.). The film thickness of each layer was calculated using a reflection spectral film thickness meter “FE-3000” (manufactured by Otsuka Electronics Co., Ltd.).

The medium refractive index layer was dried at 90 ° C. for 30 seconds, and the ultraviolet curing condition was 180 W / cm air-cooled metal halide lamp (eye graphics) while purging with nitrogen so that the atmosphere had an oxygen concentration of 1.0% by volume or less. ), And the irradiation dose was 400 mW / cm ² and the irradiation dose was 400 mJ / cm ² .

The drying condition of the high refractive index layer is 90 ° C. for 30 seconds, and the ultraviolet curing condition is a 240 W / cm air-cooled metal halide lamp (eye graphics) while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0% by volume or less. ), And the irradiation dose was 400 mW / cm ² and the irradiation dose was 400 mJ / cm ² .

The low refractive index layer was dried at 90 ° C. for 30 seconds, and the ultraviolet curing condition was 240 W / cm air-cooled metal halide lamp (eye graphics) while purging with nitrogen so that the atmosphere had an oxygen concentration of 0.1% by volume or less. ), And the irradiation dose was 400 mW / cm ² and the irradiation dose was 600 mJ / cm ² .

[Example 1: Antireflection film 102]
The high refractive index layer coating solution A in the method for producing the antireflection film 101 shown in Comparative Example 1 is changed to the high refractive index layer coating solution B described below, and further a coating method for the medium refractive index layer and the high refractive index layer. The antireflection film 102 was produced by the same production method as in Comparative Example 1 except that the following method was changed.

(Preparation of zirconium oxide dispersion Z-1)
Zirconium oxide fine particle sol (methyl ethyl ketone zirconium oxide sol, Sumitomo Osaka Cement Co., Ltd. average particle size 10 nm, zirconium oxide concentration 30%), 333 parts, 30 parts of Example I-1 of general formula [I], and diisopropoxy After adding 1.5 parts of aluminum ethyl acetoacetate and mixing, 9 parts of ion-exchanged water was added. After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature to obtain zirconium oxide fine particle dispersion Z-1 whose surface was modified with a polymer having a fluorine-containing alkyl group.
The mass concentration of zirconium oxide in the zirconium oxide dispersion Z-1 was adjusted to 30%.

(Preparation of coating liquid B for high refractive index layer)
Zirconium oxide fine particle dispersion Z-1 (zirconium oxide mass concentration 30%) 21.0 parts by mass, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate mixture (DPHA) 2.7 parts by mass, photopolymerization initiator ( Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.1 parts by mass, 73.7 parts by mass of methyl ethyl ketone and 2.5 parts by mass of cyclohexanone were added and stirred to prepare a coating solution B for a high refractive index layer. .

(Method of applying medium refractive index layer and high refractive index layer)
Multi-layer coating was simultaneously performed on a wet-on-wet using a two-slot extrusion coater.

The film thickness was set according to the flow rate when applied as a single layer.
(First slot; medium refractive index layer)
-Coating solution: Medium refractive index layer coating solution A
The flow rate of the coating solution was adjusted so that the film thickness after drying and curing was 60 nm.
(Second slot; high refractive index layer)
・ Coating liquid: High refractive index layer coating liquid B
The flow rate of the coating solution was adjusted so that the film thickness after drying and curing was 110 nm.

Drying conditions were 90 ° C. and 30 seconds, and ultraviolet curing conditions were 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the atmosphere had an oxygen concentration of 1.0 volume% or less. The irradiance was 400 mW / cm ² and the irradiation amount was 400 mJ / cm ² .
When the cross section of the film was observed with a transmission type electron microscope, there was an interface between the high refractive index layer and the middle refractive index layer, the thickness of the high refractive index layer was about 110 nm, and the thickness of the middle refractive index layer was about 60 nm. It was.
After applying the above-described medium refractive index layer and high refractive index layer, the low refractive index layer A was applied, dried and cured under the same conditions as the antireflective film 101 to produce the antireflective film 102.

[Example 2: Antireflection film 103]
The coating liquid for the medium refractive index layer and the high refractive index layer in the method for producing the antireflection film 101 shown in Comparative Example 1 was changed to the following one-liquid / two-layer coating liquid W-1 for the middle refractive index layer and the high refractive index layer. The antireflection film 103 was prepared by the same production method as in Comparative Example 1 except that the coating method was changed to the coating method of the following one-liquid / two-layer coating liquid of the medium refractive index layer and the high refractive index layer. Was made.

(Preparation of 1-liquid 2-layer coating liquid W-1 for medium refractive index layer and high refractive index layer)
Zirconium oxide fine particle dispersion Z-1 (zirconium oxide mass concentration 30%) 13.6 parts by mass and aluminum-containing zinc oxide fine particle dispersion (A-1) 7.4 parts by mass were dipentaerythritol pentaacrylate and dipentaerythritol. 2.7 parts by mass of a hexaacrylate mixture (DPHA), 0.1 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals), 73.7 parts by mass of methyl ethyl ketone, and 2.5 parts by mass of cyclohexanone Was added and stirred to prepare a one-liquid two-layer coating liquid W-1 having a medium refractive index layer and a high refractive index layer.

(Coating method of 1-liquid 2-layer coating liquid of medium refractive index layer and high refractive index layer)
On the hard coat layer A, the one- and two-layer coating liquid W-1 having a medium refractive index layer and a high refractive index layer was applied using a gravure coater. The film thickness was adjusted to 170 nm.
Drying conditions were 90 ° C. and 30 seconds, and ultraviolet curing conditions were 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the oxygen concentration was 1.0% by volume or less. The irradiance was 400 mW / cm ² and the irradiation amount was 400 mJ / cm ² .
When the cross section of the film was observed with a transmission type electron microscope, there was an interface between the high refractive index layer and the middle refractive index layer, the thickness of the high refractive index layer was about 110 nm, and the thickness of the middle refractive index layer was about 60 nm. It was.

  After applying the one- and two-layer coating solution of the above-described medium refractive index layer and high refractive index layer, the low refractive index layer A is applied, dried and cured under the same conditions as the antireflection film 101, and the antireflection film 103 is formed. Produced.

〔Evaluation methods〕
Each of the antireflection films (101, 102, 103) was evaluated by the following method.

(Integral reflectance)
The back side of the film was roughened with sandpaper, then treated with black ink, and the back side was removed, and the surface side was 380 to 780 nm using a spectrophotometer (manufactured by JASCO Corporation). In the region, the integrated spectral reflectance at an incident angle of 5 ° was measured. The arithmetic average value of the integrated reflectance of 450 to 650 nm was used for the result.

(Reflective color unevenness)
The antireflection film 1m ² of each sample was visually observed under a white fluorescent lamp, and the occurrence frequency of color unevenness of reflected light was classified and evaluated in the following three stages.
○: Reflected light color unevenness was not recognized at 1 m ² at all.
Δ: Reflected light color unevenness at one location per 1 m ² .
X: Reflected light color unevenness is 2 or more in 1 m ² .

(Adhesion)
The surface of the antireflective film having the low refractive index layer is cut with a cutter knife into a grid pattern with 11 vertical and 11 horizontal cuts, and a total of 100 square grids are engraved, made by Nitto Denko Corporation. A polyester adhesive tape (NO. 31B) was pressure-bonded and the adhesion test was repeated 5 times at the same place. The degree of peeling was evaluated according to the following four levels.
A: No peeling was observed in 100 squares.
○: Within 100 squares, peeling was observed within 2 squares.
(Triangle | delta): The thing by which peeling was recognized in 100 squares is a thing of 3-10cm.
X: A thing in which peeling was recognized in 100 squares exceeded 10 squares.

(Surface resistance value)
The surface of the antireflection film having the low refractive index layer was placed in an environment of 25 ° C. and 60% RH for 2 hours, and then the surface resistance value (SR) was measured by the circular electrode method under the same conditions. The measurement result was expressed as a logarithm of the surface resistance value (log SR).
If the log SR value is 11 or less, there is a sufficient antistatic effect.
The evaluation results according to the above evaluation method are shown in Table 3 below.

As can be seen from Table 3, in Comparative Example 1, since the medium refractive index layer and the high refractive index layer were sequentially applied layer by layer, there was reflected light color unevenness and adhesion was slightly inferior. On the other hand, in Example 1 of the present invention, the medium refractive index layer and the high refractive index layer were formed by a single application, and the production efficiency was high and the result of excellent adhesion was obtained. The reason why the antireflection film 102 of Example 1 is excellent in adhesiveness is considered to be that the interfacial bonding of the layers was good because the simultaneous multilayer coating was performed by one coating.
On the other hand, in Example 2, since the medium refractive index layer and the high refractive index layer are separated into two layers by one-layer coating,
The variation in film thickness is small with respect to the sequential application by layer performed by the antireflection film 101 of Comparative Example 1. Therefore, it is considered that the antireflection film 103 of Example 2 has less reflected light color unevenness. Moreover, in Example 2, since two layers were separated by one-layer coating, the interface bonding of the layers was good, and it is considered that good adhesion was obtained.
From these comparisons, it was found that according to the present invention, the high refractive index layer and the medium refractive index layer can be formed by a single coating process, and excellent characteristics can be obtained as compared with the prior art. .

[Example 3: Antireflection film 201]
An antireflection film 201 was produced in the same manner as in Example 1 except that the high refractive index layer coating solution B of Example 1 (antireflection film 102) was changed to the following high refractive index layer coating solution C.

(Preparation of zirconium oxide dispersion Z-2)
As a polymer having a polydialkylsiloxane group, a metal oxide fine particle dispersion whose surface was modified using Example II-1 of the general formula [II] was prepared by the following method.
Zirconium oxide fine particle sol (methyl ethyl ketone zirconium oxide sol, manufactured by Sumitomo Osaka Cement Co., Ltd., average particle size 10 nm, zirconium oxide concentration 30%), 333 parts, 40 parts of Example II-1 of general formula [II], and diisopropoxy After adding 1.5 parts of aluminum ethyl acetoacetate and mixing, 9 parts of ion-exchanged water was added. After reacting at 80 ° C. for 8 hours, the mixture was cooled to room temperature to obtain zirconium oxide fine particle dispersion Z-2 whose surface was modified with a polymer having a polydialkylsiloxane group.
The mass concentration of zirconium oxide in the zirconium oxide dispersion Z-2 was adjusted to 30%.

(Preparation of coating liquid C for high refractive index layer)
Zirconium oxide fine particle dispersion Z-2 (zirconium oxide mass concentration 30%) 21.0 parts by mass, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate mixture (DPHA) 2.7 parts by mass, photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.1 parts by mass, 73.7 parts by mass of methyl ethyl ketone and 2.5 parts by mass of cyclohexanone were added and stirred to prepare a coating solution C for a high refractive index layer. did.

[Example 4: Antireflection film 202]
The coating liquid for the medium refractive index layer and the high refractive index layer in the method for producing the antireflection film 101 shown in Comparative Example 1 was changed to the following one-liquid two-layer coating liquid W-2 for the middle refractive index layer and the high refractive index layer. The antireflection film 202 was prepared by exactly the same production method as in Comparative Example 1 except that the coating method was changed to the coating method of the following one-liquid / two-layer coating liquid of medium refractive index layer and high refractive index layer. Was made.

(Preparation of 1-liquid 2-layer coating liquid W-2 for medium refractive index layer and high refractive index layer)
Zirconium oxide fine particle dispersion Z-2 (zirconium oxide mass concentration 30%) 13.6 parts by mass, aluminum-containing zinc oxide fine particle dispersion (A-1) 7.4 parts by mass, dipentaerythritol pentaacrylate and dipentaerythritol 2.7 parts by mass of a hexaacrylate mixture (DPHA), 0.1 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals), 73.7 parts by mass of methyl ethyl ketone, and 2.5 parts by mass of cyclohexanone Was added and stirred to prepare a one-liquid / two-layer coating liquid W-2 having a medium refractive index layer and a high refractive index layer.

(Coating method of 1-liquid 2-layer coating liquid of medium refractive index layer and high refractive index layer)
On the hard coat layer A, the one- and two-layer coating liquid W-2 of the medium refractive index layer and the high refractive index layer was coated using a gravure coater. The film thickness was adjusted to 170 nm.
Drying conditions are 90 ° C. and 30 seconds, and UV curing conditions are 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the oxygen concentration is 1.0 volume% or less. The irradiance was 400 mW / cm ² and the irradiation amount was 400 mJ / cm ² .
When the cross section of the film was observed with a transmission type electron microscope, there was an interface between the high refractive index layer and the middle refractive index layer, the thickness of the high refractive index layer was about 110 nm, and the thickness of the middle refractive index layer was about 60 nm. It was.

  After applying the one- and two-layer coating solution of the above-described medium refractive index layer and high refractive index layer, the low refractive index layer A is applied, dried and cured under the same conditions as the antireflection film 101, and the antireflection film 202 is formed. Produced.

The antireflection films 201 and 202 obtained in Examples 3 and 4 were evaluated in the same manner as the antireflection films 101 to 103.
The evaluation results are shown in Table 4 below.

  As with Examples 1 and 2, the antireflective films (201 and 202) shown in Examples 3 and 4 can also form a high refractive index layer and a medium refractive index layer in a single coating process, and have excellent performance. showed that.

[Example 5: Antireflection film 301]
The coating liquid for the medium refractive index layer and the high refractive index layer in the method for producing the antireflection film 101 shown in Comparative Example 1 was changed to the following one-liquid / two-layer coating liquid W-3 for the middle refractive index layer and the high refractive index layer. The antireflection film 301 was prepared by exactly the same production method as in Comparative Example 1, except that the coating method was changed to the coating method of the following one-liquid / two-layer coating liquid of the medium refractive index layer and the high refractive index layer. Was made.

(Preparation of titanium oxide dispersion T-1)
As a polymer having a fluorine-containing alkyl group, a metal oxide fine particle dispersion whose surface was modified using Example I-2 of the general formula [I] was prepared by the following method.
Titanium oxide fine particle sol (Methyl ethyl ketone dispersion of TTO-51 (A), Ishihara Sangyo (
Co., Ltd., average particle size 30 nm, titanium dioxide concentration 30%)
2 and 40 parts of diisopropoxyaluminum ethyl acetoacetate were added and mixed, and then 9 parts of ion-exchanged water was added. After reacting at 80 ° C. for 8 hours, the mixture was cooled to room temperature to obtain a titanium oxide dispersion T-1 whose surface was modified with a polymer having a fluorine-containing alkyl group.
The mass concentration of titanium dioxide in the titanium oxide dispersion T-1 was adjusted to 30%.

(Preparation of 1-liquid 2-layer coating liquid W-3 of medium refractive index layer and high refractive index layer)
To 10.5 parts by mass of titanium oxide dispersion T-1 (titanium dioxide mass concentration 30%) and 10.5 parts by mass of aluminum-containing zinc oxide fine particle dispersion (A-1), dipentaerythritol pentaacrylate and dipentaerythritol hexa 2.7 parts by mass of an acrylate mixture (DPHA), 0.1 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.), 73.7 parts by mass of methyl ethyl ketone and 2.5 parts by mass of cyclohexanone The mixture was added and stirred to prepare a one-liquid / two-layer coating liquid W-3 having a medium refractive index layer and a high refractive index layer.

(Coating method of 1-liquid 2-layer coating liquid of medium refractive index layer and high refractive index layer)
On the hard coat layer A, a one- and two-layer coating liquid W-3 of a medium refractive index layer and a high refractive index layer was coated using a gravure coater. The film thickness was adjusted to 160 nm.
Drying conditions are 90 ° C. and 30 seconds, and UV curing conditions are 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the oxygen concentration is 1.0 volume% or less. The irradiance was 400 mW / cm ² and the irradiation amount was 400 mJ / cm ² .
When the cross section of the film is observed with a transmission type electron microscope, there is an interface between the high refractive index layer and the middle refractive index layer, the thickness of the high refractive index layer is about 80 nm, and the thickness of the middle refractive index layer is about 80 nm. It was.

  After applying the one- and two-layer coating liquid W-3 for the medium refractive index layer and the high refractive index layer, the low refractive index layer A is applied, dried and cured under the same conditions as in Comparative Example 1, and the antireflection film 301 is formed. Produced.

The antireflection film 301 of Example 5 was evaluated in the same manner as the antireflection films 101 to 103.
The evaluation results are shown in Table 5 below.

  Similarly to Examples 1 to 4, the antireflection film 301 of Example 5 was able to form a high refractive index layer and a medium refractive index layer in a single coating step, and showed excellent performance.

Claims (6)

An antireflective film in which a medium refractive index layer, a high refractive index layer, and a low refractive index layer each having a film thickness of 150 nm or less are laminated in this order on a film substrate or a film substrate having a hard coat layer. ,
The high refractive index layer contains first metal oxide fine particles having an average particle diameter of 50 nm or less, and the polymer has a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particles. The first metal oxide fine particles are surface-modified,
The middle refractive index layer contains second metal oxide fine particles having an average particle size different from the first metal oxide fine particles of 50 nm or less,
Further, the medium refractive index layer and the high refractive index layer are two layers separated from one coating film, or the middle refractive index layer and the high refractive index layer are two layers coated simultaneously by multilayer coating. the film. An antireflective film in which a medium refractive index layer, a high refractive index layer, and a low refractive index layer each having a film thickness of 150 nm or less are laminated in this order on a film substrate or a film substrate having a hard coat layer. ,
The high refractive index layer contains first metal oxide fine particles having an average particle diameter of 50 nm or less, and the polymer has a unit having a polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particles. The first metal oxide fine particles are surface-modified,
The middle refractive index layer contains second metal oxide fine particles having an average particle size different from the first metal oxide fine particles of 50 nm or less,
Further, the medium refractive index layer and the high refractive index layer are two layers separated from one coating film, or the middle refractive index layer and the high refractive index layer are two layers coated simultaneously by multilayer coating. the film. The antireflection film according to claim 1, wherein the polymer having a unit having a fluorine-containing alkyl group and a unit having a reactive group for modifying the surface of the metal oxide fine particles has a structure represented by the following general formula [I].

(In the formula, R 1 and R 2 represent a hydrogen atom or an alkyl group. L 1 represents a divalent linking group having 10 or less carbon atoms, n 1 represents 0 or 1, and R f represents —CF ₃ or —CF ₂ H. P represents an integer of 1 to 10, L represents a divalent linking group having 10 or less carbon atoms, m represents 0 or 1, A represents a hydroxyl group or a hydrolyzable group, x represents a mole %.) The antireflection film according to claim 2, wherein the polymer having a unit having the polydialkylsiloxane group and a unit having a reactive group for modifying the surface of the metal oxide fine particles has a structure represented by the following general formula [II].

(In the formula, R 1 and R 2 represent a hydrogen atom or an alkyl group. L 2 represents a divalent linking group having 10 or less carbon atoms, n 2 represents 0 or 1, and R 11 to R 15 are the same or different. Each represents a hydrogen atom or an alkyl or aryl group having 1 to 5 carbon atoms, q is an integer of 10 to 500, L represents a divalent linking group having 10 or less carbon atoms, and m is 0 or 1 represents A, A represents a hydroxyl group or a hydrolyzable group, and y represents mol%.)   The antireflection film according to claim 1, wherein the first metal oxide fine particles are fine particles of titanium oxide or zirconium oxide.   The antireflection film according to claim 1, wherein the second metal oxide fine particles are conductive zinc oxide-based fine particles.